1. Field of the Invention
The present invention relates to a device, such as a disk changer device, for storing and playing back information recorded on a recording medium such as a disk. The disk may be a CD, an MD and so forth.
2. Description of the Related Art
FIG. 6 is a block diagram which schematically shows the internal configuration of a disk changer device in a device for storing and playing back information recorded on a recording medium of the known art.
In FIG. 6, the disk changer device 100 (hereinafter simply referred to as the changer device) comprises: a playback drive 102 for driving and playing back a disk selected from disks 101, though only one disk is depicted for simplicity in FIG. 6; a decoder 103 for decoding playback signals that are driven and played back by the playback drive 102; a D/A converter 104 for performing analog conversion of the playback signals decoded in the decoder 103 so as to perform audio output of the playback signals; a contents-related information extracting unit 105 for extracting contents-related information in the disks 101 from the playback signals decoded in the decoder 103; a key operation unit 106 for inputting various commands; a display unit 107 for displaying various information; and a controller 108 for controlling the whole changer device 100.
The contents-related information corresponds to information related to tracks recorded on the disks 101, such as contents IDs for identifying the tracks, names of the tracks, and playing time of the tracks.
Next, the operation of the changer device 100 of the known art is described below.
The changer device 100 shown in FIG. 6 selects a disk to be played back from the disks 101 in the changer device 100, and places the selected disk 101 to be played back in the playback drive 102. The playback drive 102 obtains the playback signals by driving and playing back the selected disk 101, and the playback signals are supplied to the decoder 103.
The decoder 103 decodes the playback signals, and transmits the decoded playback signals to the D/A converter 104. The D/A converter 104 performs analog conversion of the playback signals so as to perform audio output thereof.
The contents-related information extracting unit 105 extracts the contents-related information from the playback signals decoded in the decoder 103, and transmits the contents-related information to the controller 108.
The controller 108 displays a part of the contents-related information on the display unit 107.
Thus, the changer device 100 of the known art drives and plays back the selected disk 101 therein so as to play back the tracks recorded on the selected disk 101. The changer device 100 also extracts the contents-related information of the tracks recorded on the selected disk 101 so as to display on the display unit 107 the names, the playing time and so forth of each of the tracks. Accordingly, a user is able to obtain the information of the track being played back while listening thereto.
According to the changer device 100 of the known art, however, it is necessary to drive and play back the selected disk 101 in the playback drive 102 for playing back the tracks. Therefore, the changer device 100 is not able to play back the tracks when the selected disk 101 is not therein.
The present invention has been made in view of the problem described above, and it is an object of the present invention to provide a device for storing and playing back information recorded on a recording medium, in which a track can be played back even if a disk is not present in the device.
To this end, according to the present invention, there is provided a device for storing and playing back information recorded on a recording medium, comprising: playback means for playing back a plurality of tracks recorded on the recording medium, to generate playback signals; memory means for storing the playback signals; history-storing means for storing recording-history information of the tracks related to the playback signals stored in the memory means; and memory control means for allowing the memory means to store in sequence the playback signals of the tracks played back by the playback means, and for allowing the history-storing means to store the recording-history information of the tracks related to the playback signals stored in the memory means.
With these features, after the recording medium has been played back and the playback signals have been stored in the storing means, a track having the playback signals stored in the storing means can be played back, even if the recording medium is not present in the device.
The recording-history information may include identification information and recording history related to the tracks stored in the memory means.
Accordingly, the stored information can be preferably managed.
Preferably, the device further comprises mode-setting means for switching between a recording medium playback mode in which the tracks recorded on said recording medium are played back by the playback means and a history-playback mode in which the tracks related to the playback signals stored in the memory means are played back by the memory control means.
Accordingly, the recording medium playback mode and the history-playback mode can be set arbitrarily.
The history-playback mode may be set by the mode-setting means when the recording medium is not present in the device and when the playback signals are stored in the memory means.
Accordingly, the history-playback mode can be automatically set without user""s mode-selection operation.
Preferably, the device further comprises: identification information detecting means for detecting identification information related to one of the tracks from the recording medium when the playback means begins to play back the track recorded on the recording medium during the recording medium playback mode; historical information determining means for determining whether or not the identification information detected by the identification information detecting means is present in the recording-history information stored in the history-storing means; and normal playback completion determining means for determining whether or not the track has been played back normally to the end, when the historical information determining means determines that the identification information is present in the recording-history information. The memory control means updates the recording history included in the recording-history information related to the track in the history-storing means as the latest information, when the normal playback completion determining means determines that the track has been played back normally to the end.
With this arrangement, the recording history information in the history-storing means can be constantly updated.
Preferably, the device further comprises: memory capacity measuring means for measuring the remaining memory capacity in the memory means when the historical information determining means determines that the identification information is not present in the recording-history information; memory capacity calculating means for calculating a required memory capacity for recording the track, on the basis of the identification information; and memory capacity determining means for determining whether or not the memory capacity calculated by the memory capacity calculating means exceeds the remaining memory capacity measured by the memory capacity measuring means. When the memory capacity determining means determines that the memory capacity calculated by the memory capacity calculating means exceeds the remaining memory capacity, the memory control means deletes the oldest playback signal from the memory means so as to produce an unused memory capacity corresponding to the required memory capacity calculated by the memory capacity calculating means, stores in sequence the playback signals of the track being played back by the playback means in the memory means, and stores the recording-history information related to the track in the history-storing means when the normal playback completion determining means determines that the track has been played back normally to the end.
With these features, the playback signals related to a new track can be stored in the storing means.
The memory control means may delete the playback signals being recorded from the memory means when the normal playback completion determining means determines that the track has not been played back normally to the end.
Accordingly, the memory capacity of the storing means can be used efficiently by preventing meaningless storing of the playback signals which have not been normally played back.
Preferably, the memory control means plays back the track related to the playback signals stored in the memory means during the history-playback mode, and updates the recording history included in the recording-history information related to the track in the history-storing means as the latest information, when the normal playback completion determining means determines that the track has been played back normally to the end.
Accordingly, the recording-history information in the history-storing means can be constantly updated.
The device may be mounted in an automobile.
With this arrangement, even if the recording medium is not present in an automobile, the track having the playback signals stored in the storing means can be played back, after the playback signals have been stored in the storing means.